The actress told IGN that she finally watched brief snippets of the Channel 4 drama at the request of director Mark Mylod.
"[He] also was part of the original team from the British series [and] said, 'You need the watch the sexuality and make sure you're cool with that amount of exposure'," she explained. "So I watched the initial sex scene in the kitchen in the British version. But that's all I've seen."
Rossum, who plays Fiona in the Showtime remake, added that she had watched the scenes "on mute, because I didn't want to hear the accents".
She admitted: "I know Anne-Marie Duff's presentation of the character is so loved and so fantastic, from everything I've read about it, so I was almost nervous to be exposed to that in any way. [I thought] that it might colour what my natural instincts would be."
Shameless airs on Sundays at 10pm on Showtime.